Touchscreen computer systems allow a user to request actions using touch gestures. Surface computing systems are table-based touchscreen computer systems that allow users to place a device on the table and the surface computing system detects the device via cameras inside the surface computing system.
The surface computing system's cameras “see” a near-IR (infrared) image of objects placed on the screen and perform functions according to loaded software programs. The surface computing system may perform functions corresponding to the object even when the object is not an electronic device. For example, a physical paintbrush may be placed on the screen and the surface computing system may be programmed to initiate a software program that allows a user to create a digital painting on the table. This is possible because, by using cameras for input, the surface computing system does not rely on electrical properties required by conventional touchscreen or touchpad devices, such as detecting the capacitance, electrical resistance, or temperature of a device.